Chromosomal assignment of porcine pregnancy-associated glycoprotein gene family.

This study presents the chromosomal assignment of a multiple pregnancy-associated glycoprotein (PAG) gene family in the domestic pig (pPAG). The pPAG locus was identified by physical mapping (fluorescent in situ hybridisation-FISH; with various probes), and additionally confirmed by Southern hybridisation of pPAG amplicons using laser microdissected Sus scrofa chromosome 1 (SSC1), as genomic templates. Various pPAG probes were produced with the use of diverse identified templates: pPAG1-6, -8, -10 cDNAs (GenBank: L34360-1, AF315377, AF272734, AY188554, AF272735, AY373029 and AY775784, respectively), or genomic DNA (gDNA) probes of pPAG2 gene and its promoter (GenBank: U39198-9, U39762-3, U41421-4). All probes, including long gDNA probes (approximately 9.2kbp GpPAG2 gene; approximately 2.8kbp GpPAG2 promoter), a shorter cDNA probe (PlpPAG4, 1385bp) and amplified pPAG2-like probes (ApPAG2L) specific for cDNA inserts of pPAG2-like gene subfamily (pPAG2, -4, -6, -8 and -10; 1283-1385bp) were produced by random priming using biotin-labelled deoxynucleotides (16-dUTP). Numerous FISH mappings with various pPAG probes revealed the chromosomal assignment of the pPAG gene family to the long arm of porcine chromosome 1 (SSC1q16-q24 region). This cytogenetic assignment was confirmed by Southern hybridisation (with (32)P-labelled pPAG10 probe) of multiple distinct pPAG amplicons (603-3943bp) produced with the use of 25 laser microdissected SSC1, as gDNA templates. This is the first study identifying the chromosomal locus of the pPAG gene family in the pig.